Is the Peak-to-Mean Pressure Gradient Ratio Useful for Assessment of Aortic Valve Prosthesis Obstruction? - Esmaeilzadeh, Maryam; Mirdamadi, Ahmad; Parsaee, Mozhgan; Sadeghpour, Anita; Maleki, Majid; Bakhshandeh Abkenar, Hooman (The Research in Heart Yield and Translational Medicine (RHYTHM))